Python Homework Sample

For any help regarding Python Homework Help
visit : - https://www.programminghomeworkhelp.com,
Email :- support@programminghomeworkhelp.com or
call us at :- +1 (315) 557-6473
For any help regarding Python Homework Help
visit : - https://www.programminghomeworkhelp.com,
Email :- support@programminghomeworkhelp.com or
call us at :- +1 (315) 557-6473

Problem
Problem
1)Is each of the following True or False
1.A greedy algorithm can be used to solve the 0-1 knapsack optimization
problem.
2.Dynamic programming can be used to solve optimization problems where the
size of the space of possible solutions is exponentially large.
3.Dynamic programming can be used to find an approximate solution to an
optimization problem, but cannot be used to find a solution that is guaranteed to
https://www.programminghomeworkhelp.com
optimization problem, but cannot be used to find a solution that is guaranteed to
be optimal.
4.In Python, an instance of a class is an object, but a class itself is not.
5.In Python, a subclass can override a function definition contained in a super
class.
6.Decision trees are always binary.

2) Provide code implementing a Python function that meets the specification below.
def findMedian(L): """Finds median of L.
L: a non-empty list of floats
Returns:
If L has an odd number of elements, returns the median element of L.
For example, if L is the list
[15.0, 5.3, 18.2], returns 15.0.
If L has an even number of elements, returns the average of the two median
If L has an even number of elements, returns the average of the two median
elements. For example, if L is the list [1.0, 2.0, 3.0, 4.0], returns 2.5.
If the list is empty, raises a ValueError exception.
Side effects: none. """

3) What does the following code print?
class Shape(object):
def __cmp__(s1, s2):
return cmp(s1.area(), s2.area())
class Square(Shape):
def __init__(self, h): self.side = float(h)
def area(self):
return self.side**2 def __str__(self):
return self.side**2 def __str__(self):
return 'Square with side ' + str(self.side)
class Circle(Shape):
def __init__(self, radius): self.radius = radius
def area(self):
return 3.14159*(self.radius**2) def __str__(self):
return 'Circle with radius ' + str(self.radius)

def f(L):
if len(L) == 0: return None x = L[0]
for s in L:
if s >= x:
x = s
return x
s = Square(4) print s.area() L =
shapes = {0:Circle, 1: Square} for i in range(10):
L.append(shapes[i%2](i)) print L[4]
L.append(shapes[i%2](i)) print L[4]
print f(L)
4) The following two formulas can be used to formalize a 0-1 knapsack problem.
1) 2)
4.1) What do each of n, pi, xi, wi, and C represent?

4.2) Use the formulas (refer to them as “formula 1” and “formula 2”) to describe the
optimization problem to be solved.
5. Write pseudo code describing merge sort.
6) Consider the two functions specified below that are used to play a “guess a
number game.”
def cmpGuess(guess):
"""Assumes that guess is an integer in range(maxVal). returns -1 if guess is < than
the magic number, 0 if it is equal to the magic number and 1 if it is greater than the
the magic number, 0 if it is equal to the magic number and 1 if it is greater than the
magic number."""
def findNumber(maxVal):
"""Assumes that maxVal is a positive integer. Returns a number, num, such
that cmpGuess(num) == 0."""
Write a Python implementation of findNumber that guesses the magic number
defined by cmpGuess. Your program should have the lowest time complexity
possible.

Problem 1
1. False. 2. True. 3. False. 4. False. 5. True. 6. False.
Problem 2
def findMedian(L):
if len(L) == 0: raise ValueError("Empty list") copy = L[:]
copy.sort()
if len(copy) % 2 == 1: return copy[len(copy) / 2]
else:
return (copy[len(copy) / 2] + copy[len(copy) / 2 - 1]) / 2
Solution
Solution
return (copy[len(copy) / 2] + copy[len(copy) / 2 - 1]) / 2
Problem 3
Problem 4
1. n — total number of items
•pi — value of item i
•xi — value is 1 if item i is taken; 0 otherwise
16.0
Circle with radius 4
Circle with radius 8

•wi — weight of item i
•C — maximum weight allotted
2. Maximize formula 1 while obeying the constraint of formula 2.
Probem 5
If the list is of length 0 or 1, then return the list Otherwise,
Divide list into left and right subsets of about the same size Sort each
sublist recursively by re-applying merge sort Merge the returned (sorted)
sublists
sublists
Problem 6
def findNumber(maxVal): """
Assumes that maxVal is a positive integer. Returns a number, num, such that
cmpGuess(num) == 0 """
s = range(0, maxVal)
return bsearch(s, 0, len(s) – 1)

def bsearch(s, first, last): if (last - first) < 2:
if cmpGuess(s[first]) == 0: return first
else:
return last
mid = first + (last - first)/2 if cmpGuess(s[mid]) == 0:
return s[mid]
if cmpGuess(s[mid]) == -1:
return bsearch(s, first, mid - 1) return bsearch(s, mid + 1, last)
"""
Assumes that guess is an integer in range(maxVal). Returns
-1 if guess is < magic number, 0 if ==, 1 if > "“”

Python Homework Sample

Recommended

Recommended

More Related Content

Similar to Python Homework Sample

Similar to Python Homework Sample (20)

Recently uploaded

Recently uploaded (20)

Python Homework Sample